1. Field of the Invention
The present invention relates to a technology for inspecting the appearance of an inspection piece and, more particularly, to a technology for inspecting the appearance of a package board by using multiple imaging means.
2. Description of the Related Art
Recently, electronic boards are used in a vast majority of equipment. Miniaturization, slim size and low price are persistent goals to be achieved in equipment in which electronic boards are used. For this purposes, high-integration design is practiced. Elements essential to achieve high-integration design include high-density packaging technology as well as availability of various design tools and advancement in semiconductor technology. Fabrication technology and inspection technology are important considerations to achieve high-density packaging. There is proposed a technology of using image recognition technology to inspect a printed board (hereinafter, referred to as a “board”) on which components are already mounted.
For example, patent document No. 1 proposes a technology adapted to a high-definition image generating apparatus for use in the field of computer graphics in which multiple inexpensive personal computers and low-resolution display apparatuses are combined. The technology enables high-definition images to be presented efficiently by distributing the workload of image generation over the individual personal computers. Further, patent document No. 2 proposes a package board appearance inspection system provided with a final result output means for outputting a final result of inspection of a package board to a management computer.    [patent document No. 1]    JP 2003-115047 A    [patent document No. 2]    JP 11-118439
While technologies are proposed for using image recognition technology to inspect a board, there is a demand for an appearance inspection apparatus characterized by high expandability and flexible system structure. Also demanded are reduction in time required to inspect a board and improvement in precision with which to inspect a board. The technology described above does not propose an appearance inspection apparatus in which an independent personal computer is capable of making a determination on its own without requiring a controller for overall control. As such, it does not achieve a system structure which is highly expandable and flexible. With the current status of technology, an extended period of time is required if inspection depends on the recognition of a high-definition image. If inspection time is reduced, inspection precision cannot be improved.